1. Field of the Invention
This invention relates to packers of the type utilized in the petroleum industry in oil and gas wells wherein it is necessary to seal off one longitudinal section of a casing from the other. Particularly, the invention is related to a packer which is retrievable after it has been used to close off the upper from a lower portion of a casing.
2. Description of the Prior Art
The use of packers in the oil and gas industry is well known. For examples of prior art teachings of packers of the type to which this invention is related, reference may be had to the following U.S. patents:
Baker et al.--U.S. Pat. No. 2,806,536 PA1 Cypher--U.S. Pat. No. 2,888,079 PA1 Levendoski--U.S. Pat. No. 2,917,114 PA1 Crowe--U.S. Pat. No. 2,998,072 PA1 States--U.S. Pat. No. 3,171,491 PA1 Kelley--U.S. Pat. No. 3,294,171 PA1 Elliston--U.S. Pat. No. 3,330,357 PA1 Mullins--U.S. Pat. No. 3,889,750
While packers are well known as indicated by the above-referenced prior art, the present invention provides improvements in packers primarily of the type for use in wells of shallow to medium depths. The packer of this invention is relatively inexpensive to manufacture compared to other known packer designs. It is substantially failproof in operation and is particularly characterized by the ease with which the packer may be inserted into and retrieved from a casing.